Printable Hydrogel Arrays for Portable and High-Throughput Shear-Mediated Assays.

Area of Science:

• Biomaterials Science
• Chemical Engineering
• Biotechnology

Background:

• Hydrogels are common for entrapping biomolecules in biocatalysis but suffer from slow solute diffusion.
• Conventional mixing methods risk damaging hydrogel structures, hindering efficient reactions.

Purpose of the Study:

• To develop a shear-stress-mediated platform, the portable vortex-fluidic device (P-VFD), to overcome diffusion limitations in hydrogel-based biocatalysis.
• To create a robust hydrogel-substrate system for enhanced reaction rates and stable biomolecule entrapment.

Main Methods:

• A portable vortex-fluidic device (P-VFD) was engineered, integrating a plasma oxazoline-coated polyvinyl chloride (POx-PVC) film with covalently bound polyacrylamide and alginate (PAAm/Alg-Ca2+) hydrogel.
• Hydrogel arrays were printed onto the POx-PVC film using a spotting machine, achieving high adhesion energy.
• The P-VFD platform was utilized to conduct biocatalytic reactions, assessing reaction rates and hydrogel stability under shear stress.

Main Results:

• The PAAm/Alg-Ca2+ hydrogel arrays demonstrated strong adhesion to the POx-PVC substrate, with adhesion energy up to 25.4 J/m2.
• Biomolecules like streptavidin-horseradish peroxidase were effectively entrapped within the shear-stress-tolerant hydrogel arrays.
• The P-VFD platform facilitated a >6-fold increase in reaction rate compared to simple incubation, attributed to overcoming diffusion limits.

Conclusions:

• The developed P-VFD platform effectively overcomes diffusion limitations in hydrogel-based biocatalysis.
• This system enables fast assay detection and efficient biocatalytic reactions without compromising hydrogel integrity.
• The shear-stress-tolerant hydrogel arrays and stable substrate offer a promising solution for advanced biocatalytic applications.